A perennial source of food

Biologist wants to cut reliance on annual crops

Hey there, time traveller!This article was published 17/8/2012 (1574 days ago), so information in it may no longer be current.

It doesn't matter how many times you say it, the phrase "grain-producing perennial polyculture" is a mouthful and a brain teaser all in one. It's been known to cause eyes to glaze over even among people familiar with the subject.

In modern agriculture, most of our grain production comes from crops that are seeded every year. This harkens back to the time when our ancestors hand-selected seeds from the plants they liked so they could grow more the next year.

Nowadays, virtually all those crops are grown in monoculture systems dependent on pesticides or tillage to ensure only the desired plants are allowed to thrive in the field.

Perennials tend to be forages, such as grasses used for livestock feed. If their seeds are harvested at all, they are used only as seed, not for food or feed.

Wes Jackson, a Kansas biologist who started The Land Institute 36 years ago, is trying to change all that. Credited as a pioneer of perennial agriculture, he was Skyped into a Winnipeg conference recently to suggest "perennial polyculture" could form the missing link between preserving the environment and feeding the world.

We've been cultured to believe it's a trade-off. You can have production at the expense of conservation or you can have conservation at the expense of production. Conventional wisdom is we need to maximize production on agricultural lands to avoid destroying the natural lands that remain.

"We are saying we can have conservation as a consequence of production," he told the North American Prairie Conference.

How? By developing perennial crop species that coexist in fields, much like the native prairie ecosystem, and which can be harvested annually. The system would mostly rely on the sun rather than fossil fuel for energy, and would build soil health and preserve water quality and biodiversity. But could it produce enough food?

It sounds a bit far-fetched. After all, if perennial agriculture was the way to go, why didn't the world's first farmers go there? Jackson thinks it is because they lacked the tools and the time to make the genetic selections and crosses to either make annual grain crops perennial or make perennial crops produce enough harvestable seed.

Scientists exploring these concepts today are using modern techniques such as molecular markers, which allow genetic traits to be identified and tracked as crosses and selections are made. However, Jackson said developing successful perennial crops probably can't be accomplished through genetic modification, which tends to focus on single traits. Perennial is a "way of life," meaning a host of traits relying on multiple genes go into making a plant capable of perpetual survival. Even if all those traits could be separated into specific genes, it would cost too much to do all that gene jockeying.

Many would say this is all just a big waste of time. Modern agriculture based on annual cropping and monoculture has proven to be remarkably productive and effective at keeping Malthusian predictions at bay -- at least so far.

Jackson counters that all this productivity is based on a false economy -- cheap fossil fuel. "The world we are likely to be living in before this century is out is going to see a great reduction in fossil fuels for power," he said.

So far, alternatives such as nuclear power or bio-energy have been unable to come anywhere close to filling the gap. In fact, the push to develop ethanol and biodiesel is controversial, especially now, when much of the U.S., the world's largest corn exporter, is withering under a drought. There's currently a big push to waive the legislated mandate requiring a percentage of U.S. fuel to be blended with biofuels, because with more than 40 per cent of recent corn production now going into gas tanks, food and feed users might go without.

"What we have yet to appreciate is how much of what I call the scaffolding of human civilization was put there by high-density carbon," Jackson says.

In addition to a dependence on non-renewable resources, modern food production has proven costly in other ways, such as dead zones in the oceans and eutrophication of freshwater bodies due to excessive nutrient runoff.

Jackson, who was named one of the 100 most influential Americans by Time-Life magazine, is far from alone in his quest for a more sustainable food supply based on perennial plants. There are now pockets of research taking place all over the world, including right here at the University of Manitoba.

For those of us still struggling to envision what a sustainable grain-producing perennial polyculture might look like, Jackson makes it easy. He calls it a prairie.

Laura Rance is editor of the Manitoba Co-operator. She can be reached at 204-792-4382 or by email: laura@fbcpublishing.com

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